Dolastatin 3 was first isolated and elucidated by Dr. George R. Pettit and found to possess potent cell growth inhibitory powers (See U.S. Pat. No. 4,414,205 for detailed history). However, the vast number of Dolabella needed to provide sufficient Dolastatin 3 to meet the projected public need effectively prevented this remarkable substance from ever being considered for commercial production. Further, the inability to tightly replicate the natural substance from lot to lot because of the entrainment of even slight amounts of unidentifiable impurities in the extracted product created problems which prevented the natural substance from meeting the strict uniformity requirements set forth by the Food and Drug and Cosmetic Administration and corresponding regulatory agencies in other countries as a condition precedent to the approval of the introduction of a new drug product to the market place.
Thus, the need to develop an economically viable and truly replicable synthetic procedure for producing substantially pure Dolastatin 3 in large quantities is the principal object of the present invention.